Gold and platinum are precious metals used in jewelry. Gold is alloyed with other metals like silver and copper to increase its strength for everyday wear, with higher karat weights containing more gold. Common karat weights are 14k and 18k gold. Platinum is a silver-white, durable metal that is up to 95% pure and ideal for setting diamonds due to its hardness and ability to securely hold gems without discoloration. Both metals are valued for their rarity, strength, and resistance to tarnish.